As a wireless operation terminal that remotely controls an information processing apparatus such as a television receiver, an infrared remote controller utilizing an infrared communication has been a mainstream. However, the infrared remote controller has a high directivity of an infrared ray, and hence it has been necessary to direct the remote controller, a light-emitting unit of an infrared ray, to a control-target apparatus. However, the directivity of a radio wave is relatively low, and hence, in recent years, a radio frequency (RF) remote controller utilizing a high-frequency radio wave has been developed and is becoming a mainstream. Further, attempts to standardize the RF remote controller are conducted by organizations.
For example, in accordance with near field communication standard IEEE (registered trademark) (institute of electrical and electronic engineers) 802.15.4, ZigBee (registered trademark) is standardized as specifications for a network layer, a security layer, and an application layer, which correspond to upper layer of IEEE (registered trademark) 802.15.4. In addition, based on IEEE (registered trademark) 802.15.4, RF remote control standard ZigBee (registered trademark) RF4CE (radio frequency for consumer electronics) is standardized by trade organizations.
For example, Patent Document 1 discloses a technique relating to an operation terminal that controls an information processing apparatus such as a television receiver using an RF wireless signal such as RF4CE. Further, Patent Document 2 describes a remote control apparatus including a casing formed of a six-sided rectangular parallelepiped, which has two main surfaces in which operation keys are provided. This remote control apparatus detects which of the two main surfaces is on the front side and invalidates an operation key of the main surface on the back side.    Patent Document 1: Japanese Patent Application Laid-open No. 2011-034294    Patent Document 2: Japanese Patent Application Laid-open No. HEI 6-89634